[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Help-glpk] On strict inequalities conversion

From: Paulo J. Matos
Subject: [Help-glpk] On strict inequalities conversion
Date: Mon, 6 Feb 2006 19:08:22 +0000

On a reply by Andrew Makhorin dated Fri, 9 Aug 2002 20:10:32 +040:

Andrew says the one can transform a lower strict bound to a lower weak bound as:
eps = 10.0 * lpx_get_real_parm(lp, LPX_K_TOLBND);
new_lb = old_lb + eps * (1.0 + fabs(old_lb));

Why not ?
new_lb = old_lb + lpx_get_real_parm(lp, LPX_K_TOLBND);

Still, if I have an upper bound not in a variable but a constraint upper bound:
maximize 0: (which means I don't need to maximize, I need _any_ solution)
sum a_i x_i < b

can I do:
eps = 10.0 * lpx_get_real_parm(lp, LPX_K_TOLBND);
newb = b - eps*(1.0 + fabs(b));

and solve
sum a_i x_i <= newb?

Is this the correct way (best way) to work around this issue?

Paulo Jorge Matos - pocm at sat inesc-id pt
Computer and Software Engineering

reply via email to

[Prev in Thread] Current Thread [Next in Thread]